Fix t/f/return.py, tweak handle_binary_ops

tests/passing_tests/return.py

@@ -0,0 +1,17 @@
+from pythonbpf import compile, bpf, section, bpfglobal
+from ctypes import c_void_p, c_int64
+
+
+@bpf
+@section("sometag1")
+def sometag(ctx: c_void_p) -> c_int64:
+    return c_int64(1 - 1)
+
+
+@bpf
+@bpfglobal
+def LICENSE() -> str:
+    return "GPL"
+
+
+compile()